In the Nebraska license plate system, Cass County is represented by the prefix 20 (it had the twentieth-largest number of vehicles registered in the county when the license plate system was established in 1922).

Adjacent counties

Due to its proximity to Cass County, Iowa, and because both of those counties receive most of their broadcasts from Omaha, Nebraska, references to 'Cass County' must be frequently disambiguated, or result in confusion.[citation needed]

There were 9,161 households out of which 35.80% had children under the age of 18 living with them, 63.30% were married couples living together, 7.60% had a female householder with no husband present, and 25.70% were non-families. 21.60% of all households were made up of individuals and 9.40% had someone living alone who was 65 years of age or older. The average household size was 2.63 and the average family size was 3.07.

In the county the population was spread out with 27.90% under the age of 18, 7.00% from 18 to 24, 29.00% from 25 to 44, 23.80% from 45 to 64, and 12.30% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 97.70 males. For every 100 females age 18 and over, there were 95.00 males.

The median income for a household in the county was $46,515, and the median income for a family was $52,196. Males had a median income of $36,639 versus $24,612 for females. The per capita income for the county was $20,156. About 4.20% of families and 5.20% of the population were below the poverty line, including 7.10% of those under age 18 and 4.50% of those age 65 or over.